Polls and Facebook at odds over Ireland abortion vote

While opinion polls show a comfortable lead for the pro-choice side in an upcoming referendum on abortion in Ireland, one survey indicates pro-life groups are winning the enthusiasm battle on Facebook. They've created a database of Facebook posts and ads, including so-called "Dark adverts" - those which are only seen by the intended audience, and generally not seen by the rest of Facebook users. Perhaps the most notable recent example was the 2016 US presidential election, where huge Facebook enthusiasm could be seen for Donald Trump, despite his campaign lagging in the polls and his loss in the popular vote. Theresa Hong, who wrote Trump's Facebook posts, told the BBC last year: "Without Facebook we wouldn't have won." BBC Trending analysed pro-Jeremy Corbyn posts and groups on Facebook before and after the 2017 general election, and social media chatter about the Labour leader may have been an important factor in his over-performance compared to pre-election polls.